将 Http 基本身份验证添加到 servletRequest答案

【问题标题】：Add Http Basic Authentication to servletRequest将 Http 基本身份验证添加到 servletRequest
【发布时间】：2017-05-25 10:30:58
【问题描述】：

我有一个ProxyServlet 来处理从我的应用程序发送到另一台服务器（使用 HTTP 基本身份验证）的请求，我想在 Servlet 触发实际请求之前手动添加标头，这样用户就不必输入任何凭据。

我使用HttpServletRequestWrapper尝试了类似下面的代码

public class DataServlet extends ProxyServlet {
  @Override
  protected void service(HttpServletRequest servletRequest, HttpServletResponse servletResponse)
        throws ServletException, IOException {

    final SystemCredentials credentials = new SystemCredentials("username", "password");

    HttpServletRequestWrapper wrap = new HttpServletRequestWrapper(servletRequest){

        @Override
        public String getHeader(String name) {              
            if (name.equals("Authorization")){
                String encoding = Base64.getEncoder().encodeToString((credentials.getUser().concat(":").concat(credentials.getPassword()).getBytes()));
                return "Basic " + encoding;
            } else
                return super.getHeader(name);
        }

    };

    super.service(wrap, servletResponse);

  }
}

它似乎不起作用，当我尝试访问它时，会显示一个弹出窗口并询问远程服务器的凭据。

我的 web.xml 包含

<servlet>
  <servlet-name>data</servlet-name>
  <servlet-class>foo.package.servlet.DataServlet</servlet-class>
  <init-param>
    <param-name>targetUri</param-name>
    <param-value>http://fooServer/DataServer</param-value>
  </init-param>
  <async-supported>true</async-supported>
</servlet>
<servlet-mapping>
  <servlet-name>data</servlet-name>
  <url-pattern>/DataServer/*</url-pattern>
</servlet-mapping>

还有其他方法可以使这项工作吗？

谢谢！

【问题讨论】：

标签： java http servlets basic-authentication request-headers

【解决方案1】：

解决方案是覆盖方法 getHeader(String name) 、 getHeaders(String name) 和 getHeaderNames() ，如下所示。这也取决于实现如何寻找标头。在这种情况下，ProxyServlet 正在通过 Enumeration<String> getHeaders(String name) 查找。

HttpServletRequestWrapper wrap = new HttpServletRequestWrapper(servletRequest){


        @Override
        public String getHeader(String name) {

            if (name.equals(HttpHeaders.AUTHORIZATION)){
                String encoding = Base64.getEncoder().encodeToString((credentials.getUser().concat(":").concat(credentials.getPassword()).getBytes()));
                return "Basic " + encoding;
            }
            return super.getHeader(name);
        }

        @Override
        public Enumeration<String> getHeaders(String name) {
            if (name.equals(HttpHeaders.AUTHORIZATION)){
                List<String> temp = new ArrayList<>();
                String encoding = Base64.getEncoder().encodeToString((credentials.getUser().concat(":").concat(credentials.getPassword()).getBytes()));
                temp.add("Basic " + encoding);
                return Collections.enumeration(temp);
            }
            return super.getHeaders(name);
        }

        @Override
        public Enumeration<String> getHeaderNames() {
            // TODO Auto-generated method stub
            List<String> temp = Collections.list(super.getHeaderNames());
            temp.add(HttpHeaders.AUTHORIZATION);
            return Collections.enumeration(temp);

        }

    };

【讨论】：